1. Field of the Invention
The present invention relates generally to the field of hydrolasing tools for deployment in storage tanks. More specifically, the present invention discloses a remotely-operated hydrolasing system for mobilizing hardened salt cake in large storage tanks.
2. Statement of the Problem
A number of hazardous waste storage facilities around the country have large underground storage tanks containing hardened salt cake. A problem exists in dissolving or mobilizing these salts, so that they can be removed from the storage tanks for treatment or disposal. The conventional approach has been to sluice water through the storage tanks to dissolve the salt cake. This has been less than completely satisfactory in breaking down salt cake due to the hardened nature of the salt cake and its limited solubility.
In more accessible environments, salt cake can be more effectively removed from surfaces by means of high-pressure jets of waters. This is commonly known as “hydrolasing,” However, hydrolasing presents a number of major obstacles to its use in underground storage tanks and in dealing with hazardous waste. The primary obstacle is a lack of access provided when dealing with large underground storage tanks. For example, many storage tanks have a 12-inch diameter opening and a 9-foot riser leading into the interior of the tank. The bottom of the tank can be more than 50 feet below the surface of the earth. In addition, the tank may contain obstacles must be maneuvered around. These limitations create significant obstacles to deploying, operating and recovering a hydrolasing apparatus within a storage tank.
Dealing with hazardous wastes creates additional obstacles. The hydrolasing head must have sufficient power to break apart and mobilize the waste in order to be effective. However, it should be unable to penetrate the corroded steel wall of the tank, which might release hazardous waste into the surrounding environment. In addition, the hydrolasing process should minimize the generation of aerosols that can escape through the riser into the environment.
3. Solution to the Problem
The present invention addresses the shortcomings of the prior art by providing a hydrolasing system that can be readily deployed in and recovered from underground storage tanks. Once deployed within a storage tank, the hydrolasing system can be maneuvered on its drive wheels to avoid obstacles and allow careful control of the areas of the tank to be treated.